Anti-friction bearings serve to decrease friction of and provide support for, for example, a hub upon which a wheel is mounted, for instance, to rotate about a spindle. Such bearings may comprise roller bearings, for example, tapered roller bearings. The spindle may comprise, for instance, an axle or a shaft.
A typical tapered roller bearing includes a cone having an inner race for mounting on a spindle, a cup having an outer race for mounting in a hub, and a plurality of roller elements within a roller cage positioned between the inner and outer races. Commonly, a pair of such tapered roller bearings are mounted on a spindle for rotation thereabout of a wheel mounted on a hub. Cooperating bearings, such as a pair of tapered roller bearings, may be included in a bearing assembly.
In order to properly secure bearings in many axle, spindle, and transmission assemblies, it is necessary to retain the bearings tightly under a predetermined axial load on the shaft or axle, so that they will maintain the proper running clearance of the roller elements under the influence of the combined axial and radial forces which they are designed to support. It is often the practice of manufacturers of such assemblies to carefully measure the space between the bearing inner races, and provide a spacer of precisely the correct dimension and load requirements to fit therebetween. The spacer is often made of ground steel tubing to a length tolerance of plus or minus one half of one thousandth of an inch. If the bearings are not maintained at a proper load the bearings may not roll properly or may prematurely wear, particularly if the bearings are maintained at too high of a load, or may, if maintained under too low of a load, have excessive play causing failure of the bearings and wheel supported thereon.
Certain assemblies employ an adjustable spacer or load ring which can be fitted by means of loading within the assembly. In assemblies which are subject to high loading during service, it may be required that the spacer have a very high capacity to resist being deformed. In one example, an adapter sleeve optionally may be employed in conjunction with the spacer between a pair of roller bearings, such as for accommodation of differing spindle dimensions at each bearing location.
An exemplary embodiment of such an adapter sleeve and adjustable spacer is disclosed in commonly owned U.S. Pat. No. 5,549,397 to Rode (entitled "Adapter Sleeve and an Adjustable Spacer With Radial Extension Useable Thereon" and issued Aug. 27, 1996) and in commonly owned U.S. application Ser. No. 08/661,349 of Rode (entitled "Adjustable Bearing Assembly and Adapter Sleeve Therefor" and filed Jun. 14, 1996), which are hereby incorporated herein by reference in their entireties.
One approach to preparing a bearing assembly with an adjustable spacer which is subject to high-shock loading, requires sensing of the resistance to rolling torque that is encountered when a tapered roller bearing is loaded axially. The sensed resistance is used as an indicator of whether the bearings are correctly positioned.
However, some assemblies do not permit such an approach, such as where the bearing is pre-assembled as a cone and cup assembly with a lubrication seal. In particular, the seal, when new, can cause a significant resistance to rolling torque, thereby interfering with the ability to sense the rolling drag of a lightly-preloaded bearing.
In other designs, it may be preferable to use a method of adjusting the spacer without relying upon torque resistance measurement. Unfortunately, such a method can undesirably require the making of dimensional measurements, which are desirable to avoid since they are time-consuming and allow errors to be introduced by the assembler.
Thus, a need exists for improving performance, easing use, and increasing adjustability of an adjustable spacer employed with a bearing assembly. A further need exists for improving ease, accuracy, and control of adjustment to an adjustable spacer employed with a bearing assembly. A need also exists for decreasing dimensional measurements required to properly prepare a spacer and bearing assembly. An additional need exists for decreasing the number of parts, and attendant positioning complexity, required to satisfy a function provided by an adapter sleeve and an adjustable spacer employed with a bearing assembly.